This invention relates to the detection and signal processing of electrical brain activity. The purposes of this invention include the detection of information processing undertaken in the brain, the detection of concealed information in the brain, communication from the brain to a computer, and command and control of computers and electronic and mechanical equipment by the brain.
The Farwell MERA System is a new technology for the detection of concealed information that revolves around the non-invasive recording of brain electrical activity. The electrical brain activity pattern recorded and of interest is a specific multifaceted electroencephalographic response (MER) that occurs immediately after an examinee is visually presented (via a computer screen) with words, short phrases, acronyms, or pictures that are recognized and cognitively processed by that subject. This phenomenon, coupled with its absence following the presentation of the same information to a subject for whom the material is unknown or irrelevant, is the basis for discriminating between subject guilt and innocence. This would potentially allow for the determination of a whole host of issues of interest to the law enforcement and intelligence communities, e.g., (1) does a suspect have guilty knowledge connecting him to specific investigated criminal activity, (2) does an intelligence source have knowledge of the internal workings of a hostile intelligence agency that would indicate that he was an intelligence officer of that agency and not who he claimed to be, (3) has an informant, a debriefed spy, or a suspected member of a criminal organization accurately described the entirety of his actions and knowledge, (4) did a convicted serial killer who claims to have killed 40 to 50 individuals, other than the one(s) he was convicted of, actually commit these acts, or are these claims merely the bravado of a condemned prisoner.
The potential benefit of this program extends to a broad range of law enforcement applications, including organized crime, violent crime, white-collar crime, drug-related crime, foreign counterintelligence, non-traditional targets, and other categories of casework as well. This new technology promises to be of tremendous benefit both at the national level and for state and local law enforcement agencies.
This application describes a technology that is capable of detecting concealed information stored in the brain through the electrophysiological manifestations of information-processing brain activity. Additional information is described in a previous patent application of the inventor, U.S. patent application Ser. No. 08/016,215, entitled "Method and Apparatus for Truth Detection" filed on Feb. 11, 1993, which is expressly incorporated here by reference.
This technique provides a means of distinguishing guilty and innocent individuals in a wide variety of law enforcement and information detection situations. The research described below demonstrates that the system is also effective in distinguishing between members of a particular organization (in this case, the FBI) and others who are not knowledgeable regarding that organization.
When a crime is committed, traces of the event are left at the scene of the crime and elsewhere. The task of the investigators is to reconstruct what has happened and who has been involved, based on the collection of such evidence.
In addition to the physical and circumstantial evidence that can be obtained, there is one place where an extensive record of the crime is stored: in the brain of the perpetrator. If this record could be tapped, criminal investigation and counterintelligence could be revolutionized.
Until recently, the only method of attempting to discern what information regarding a crime or other situation of interest was stored in the brain of a suspect or witness has been (1) to interrogate the subject, and (2) to attempt to determine whether or not the subject is lying.
Conventional control question (CQT) polygraphy has been used as an aid in the attempt to detect deception in such reports. The fundamental theory of conventional polygraphy is that a deceptive individual will be more concerned with and experience more emotional arousal in response to relevant questions than control questions, and this emotional arousal will be accompanied by corresponding physiological arousal which can be measured. Traditional interrogative polygraph ("lie detection") methods rely upon using questioning formats in conjunction with the recording of physiological parameters that reflect autonomic nervous system (ANS) activity (e.g. blood pressure, heart rate, sweating, etc.). This information is peripheral to the cognitive aspects of deception or of concealing guilty information.
Multifaceted electroencephalographic response analysis (MERA) technology focuses on the origins (at the level of subject recognition of guilty knowledge) of concealed information rather than the peripheral physiological manifestations of that knowledge. In addition to being a more direct physiological approach (central nervous system vs. peripheral) to the question at hand, the Farwell MERA System may well overcome certain difficulties inherent with standard polygraphy: (1) Innocent as well as guilty individuals may respond emotionally and physiologically to crime-relevant questions, which may result in an innocent subject falsely being found deceptive; (2) guilty individuals may fail to respond in the expected way either emotionally or physiologically; (3) certain mental and physical countermeasures can be practiced successfully with standard technology; and (4) a conventional polygraph exam is highly stressful for the examinee, and involves deception by the polygrapher.
In a conventional polygraph test, emotion-driven physiological responses to relevant questions (regarding the situation under investigation) are compared to responses to control questions, which are invasive, personal questions not relevant to the issue at hand that are designed to be emotionally and physiologically disturbing to the subject. A greater response to the relevant questions leads to a deceptive ("guilty") determination; a greater response to the control questions leads to a non-deceptive ("innocent") determination. In an attempt to avoid a false positive result (non-deceptive subject falsely found deceptive), the examiner must ask penetrating questions in the pre-test interview to find personal material sufficiently disturbing and stress-producing to produce effective control questions. To elicit a stress response to the control questions during the test, the examiner typically deceives the subject, leading him to believe that a large response to control questions will make him appear guilty (deceptive), rather than innocent (non-deceptive). This deception by the examiner is necessary, or at least highly instrumental, to produce the response. Thus, in conventional polygraphy, innocent subjects--even if they are correctly determined to be innocent and truthful--are deceived and subjected to a highly invasive and stressful situation both during the pre-test interview and during the test.
This latter shortcoming is generally justified by the correct end result of finding an innocent subject non-deceptive to the relevant questions, but could be avoided altogether with MERA technology, which depends entirely on information processing brain activity (i.e., recognition and processing of significant information) rather than an artful and disturbing manipulation designed to produce emotional and physiological responses to control question material. In fact, the pre-test interview for a MERA-based exam is a very clinical, emotionally neutral experience for both guilty and innocent subjects. The in-test portion of the MERA-based exam does not involve the asking of any questions, only the non-invasive recording of brain electrical activity as a subject views verbal or pictorial information on a computer screen.
A new study conducted by the inventor in collaboration with SSA Drew C. Richardson, Ph.D., FSRTC, FBI Laboratory, described below, has shown the Farwell MERA System to be capable of detecting whether or not an individual has participated in FBI new agent training at the Academy. New FBI agents in training at the FBI Academy at Quantico were correctly identified as such, and individuals unfamiliar with the FBI were also correctly classified. The application of this technique in foreign counterintelligence is obvious: if this technology can be utilized to detect an FBI agent, it can also be used to detect agents of other organizations, including both intelligence organizations and international criminal organizations. The detection of information stored in the brain is indeed central to the investigation of all types of crimes--e.g., organized crime, violent crime, white-collar crime, drug-related crime, industrial espionage, non-traditional targets--as well as foreign counterintelligence operations.
Although several previous experiments, including those reported in the above cited United States patent application incorporated here by reference, used an experimental design that included some of the major features specified herein, the MERA technique was not practiced in the prior art, the MERMER was not detected and characterized in previous experiments, and the MERMER was not used in the analysis procedures implemented to detect which information was noteworthy for the subject. For this reason, all other previous methods lacked a critical and central feature in the effectiveness of the present invention.
There are several reasons why the MERMER was not detected in previous experiments. Previous experiments were structured so as to detect only the well-known P3b or P300, and failed to detect the MERMER (e.g., the following references cited in the above cited U.S. patent application included herein by reference: Farwell and Donchin, 1986; 1991; Rosenfeld et al., 1987, 1991; see also Farwell, U.S. Pat. No. 4,941,477; Rosenfeld, J. P., Cantwell, B., Nasman, V. T., Wojdac, V., Ivanov, S. and Mazzeri, L., A modified, event-related potential-based guilty knowledge test, International Journal of Neuroscience, 1988, 42, 157-161; Rosenfeld, U.S. Pat. No. 4,932,416). These and all other previous experiments failed to detect the frontally prominent, late negative facet of the MERMER and the frequency domain changes that characterize a MERMER. There are several reasons for this:
(A) Time domain responses (event-related potentials)
(1) The P300 or P3b, the response sought in previous experiments, is maximal at the parietal scalp location, and the negative facet of the MERMER has a considerably different scalp distribution, particularly when difference waveforms are taken into account. Previous experiments focused on the parietal, or in some cases central, scalp locations, and thus did not detect or did not accurately characterize the late, frontally prominent, negative potential that characterizes a MERMER. PA1 (2) The frontally-prominent, negative facet of the MERMER does not begin until about one second after the stimulus, and does not peak until up to 1600 msec after the stimulus. Earlier experiments analyzed only a limited time epoch, and thus this negative component was not accurately or fully represented in the data analyzed. PA1 (3) In some previous experiments, the inter-stimulus interval was only about 1500 msec, and/or the data collection epoch was only a little over one second. Such an interval is insufficient for the frontally prominent, negative component of the MERMER to develop fully. PA1 (1) All similar previous experiments analyzed the data only in the time domain. The frequency-domain changes that characterize a MERMER can not, of course, be detected in the time domain. PA1 (2) All similar previous experiments involving detection of concealed information or brain-to-computer communication used signal averaging as a means of noise reduction, and applied their detection methods to averaged signals. Although the alternating-current, frequency-domain signals change in response to the stimulus, these signals are not phase-locked to the stimulus, and therefore the frequency-domain changes are eliminated by signal averaging. PA1 (3) Previous research on frequency-domain changes (e.g., on alpha blocking), all differ from the present invention in that they did not use similar stimulus presentation designs, did not detect specific or concealed information, did not communicate specific information in the manner accomplished by the present invention, did not simultaneously measure and process time-domain changes (in fact, the analog filters used in previous research for frequency domain data markedly attenuate or virtually eliminate the very slow activity in the range of 0.1 to 2 Hz that contributes to the MERMER) did not process time frequency data, and did not use the signal processing methods (e.g., bootstrapping correlation) described herein. PA1 1) Farwell, L. A. (1992a). The Brain-wave Information Detection (BID) System: A New Paradigm for Psychophysiological Detection of Information. Doctoral Dissertation, University of Illinois at Urbana-Champaign. PA1 2) Farwell, L. A. (1992b). Two New Twists on the Truth Detector: Brain-wave Detection of Occupational Information. Psychophysiology, 29,4A:S3.
In order to characterize the time-domain facets of the MERMER accurately, and to extract the full complement of data it provides in the time domain, it is necessary to analyze the frontal as well as parietal and central data, for 1.8 to 2 seconds after the stimulus. Farwell and Donchin (1991) did analyze frontal data, but their analysis epoch ended 1200 msec after the stimulus onset, and the inter-stimulus interval was only 1550 msec: both of these are too short to allow for the occurrence or detection of the negative component. Thus, Farwell and Donchin concluded that the frontal scalp location did not contribute to the critical discrimination between brain responses. Rosenfeld et al. (1991) observed some late negativity at the parietal scalp location in a similar experimental design, but did not analyze the data from the frontal site in making their discriminations between brain responses to different types of trials, and did not identify or report the frontal-negative aspect of the MERMER (they did collect frontal data). None of the above researchers recognized or described the MERMER as a phenomenon.
(B) Frequency domain
In addition to the references cited in the above cited United States patent application incorporated here by reference, the inventor published research on the psychophysiological detection of concealed information in the following scientific publications. None of the material constituting the inventions claimed herein was presented.
Numerous other systems have been developed to communicate with a computer. None have features that approximate the present system. Neither MERA nor the MERMER were used in previous systems.
Farwell and his colleagues developed a system based on the P3 component (described in the above cited United States patent application incorporated here by reference). That system, however, was unable to make use of the MERMER, because 1) the maximum inter-stimulus interval used was 600 msec, and a MERMER can take as long as 2000 msec to develop fully; 2) only the parietal scalp location was recorded. Thus the system failed to detect both the frontal negative facet and the frequency domain facets of the MERMER.
The task undertaken to elicit a MERMER is more cognitively complex, and more memory-intensive, than the tasks used to focus attention on the chosen item in previous attempts to use brain electrical activity to provide an interface with a computer. For example, Farwell and Donchin used a simple counting task (Farwell, L. A., and Donchin, E., Talking off the top of your head: toward a mental prosthesis utilizing event-related brain potentials, Electroencephalography and Clinical Neurophysiology, 1988, 70: 510-523). This could be expected to elicit a P300, but probably would not have been effective in eliciting a MERMER, even if they had recorded a long enough data epoch to detect a MERMER.
Dr. John Wolpaw of Stoneybrook and his colleagues (personal communication) have developed a system to move a cursor on a computer screen using feedback and analysis of electrical brain activity. This system is essentially a biofeedback system, and, unlike the present system, does not detect the information-processing activity involved in conscious choice and memory, nor has it been used to command a speech synthesizer, a robot, a computer function beyond simply moving the cursor on the screen, or any mechanical device.
Sutter (Sutter, E. E., An oculo-encephalographic communication system. In: Proceedings of the 6th Annual Conference of Rehabilitation Engineering, San Diego, 1983: 171-173.) developed a system to use visual sensory evoked potentials to convey to a computer where a subject's eyes are pointed, wherein the subject conveys his choice by engaging in the motor activity of pointing the eyes to a certain location, and subsequent sensory evoked potentials elicited by a flashing light at the particular location are detected to convey to the computer where the eyes are pointed. That system, of course, has nothing to do with detecting the brain responses that reflect the cognitive, information-processing activities that are involved in making the conscious choices detected by the present system. Unlike the present system, the choices are followed by a motor activity (moving the eyes to a particular location), and detected on the basis of sensory activity (responses to a flashing light at the location); the detection of cognitive, information-processing activity related to choice, stimulus significance, and memory is lacking.
None of the above publications disclose the innovations that constitute the invention claimed herein.